A method is known for entering a graphical password which requires a user to touch, via a mouse, areas of a graphical image on a display in a predetermined sequence (U.S. Pat. No. 5,559,961, IPC G06F 11/00, published on Sep. 24, 1996).
The password, however, suffers from insufficient security. Firstly, an unauthorized person can oversee and repeat the process of entering data of the password. Secondly, the number of password patterns that could be generated is small and the patterns are easy to produce by trial and error. In addition to the insufficient security, the prior art method suffers one problem more—not every password selected by the user can be easily memorized. To gain access to numerous databases, the user must remember a plurality of different password patterns, which becomes impossible due to abundance of such systems.
A method is also known for entering a password, involving the use of changing graphical images, such as digits, which requires a user to perform logical operations, such as subtraction, on images of digits that are displayed and conceived (JP Patent No. 6-214954, IPC G06K 15/00, 3/02, published on Aug. 5, 1944). Security provided by the method is quite high, but the required additional logical operations increase load on the user.